diff options
| author | Copilot <[email protected]> | 2025-11-12 04:34:34 +0800 |
|---|---|---|
| committer | GitHub <[email protected]> | 2025-11-12 04:34:34 +0800 |
| commit | e525c38cb8d742d6d5b9f879ddfa588d3e1fcf71 (patch) | |
| tree | 27201a275f36ca24a6ff5feb44a99e608d5cc660 /libcpu/arm | |
| parent | 284081fe4c21a52efdcef53dda4881b83b6445f2 (diff) | |
[libcpu][cortex-a] Refactor FPU stack initialization for maintainability (#10919)
* Initial plan
* [libcpu][cortex-a] Improve FPU stack initialization implementation
Co-authored-by: BernardXiong <[email protected]>
* [libcpu][cortex-a] Replace FPU init loop with rt_memset
Co-authored-by: BernardXiong <[email protected]>
---------
Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: BernardXiong <[email protected]>
Diffstat (limited to 'libcpu/arm')
| -rw-r--r-- | libcpu/arm/cortex-a/cpuport.h | 5 | ||||
| -rw-r--r-- | libcpu/arm/cortex-a/stack.c | 8 |
2 files changed, 12 insertions, 1 deletions
diff --git a/libcpu/arm/cortex-a/cpuport.h b/libcpu/arm/cortex-a/cpuport.h index 5fb067999c..c18ae246b2 100644 --- a/libcpu/arm/cortex-a/cpuport.h +++ b/libcpu/arm/cortex-a/cpuport.h @@ -72,6 +72,11 @@ struct rt_hw_stack #define E_Bit (1<<9) #define J_Bit (1<<24) +/* VFP/NEON register count for FPU context */ +#ifndef VFP_DATA_NR +#define VFP_DATA_NR 64 /* 32 double-precision registers = 64 words */ +#endif + #ifdef RT_USING_SMP typedef union { unsigned long slock; diff --git a/libcpu/arm/cortex-a/stack.c b/libcpu/arm/cortex-a/stack.c index 4c955677f8..5bb57ca4dd 100644 --- a/libcpu/arm/cortex-a/stack.c +++ b/libcpu/arm/cortex-a/stack.c @@ -61,7 +61,13 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter, *(--stk) = 0; /* user sp*/ #endif #ifdef RT_USING_FPU - *(--stk) = 0; /* not use fpu*/ + /* FPU context initialization matches context_gcc.S restore order: + * Stack layout (high to low): FPEXC -> FPSCR -> D16-D31 -> D0-D15 + */ + stk -= VFP_DATA_NR; + rt_memset(stk, 0, VFP_DATA_NR * sizeof(rt_uint32_t)); /* Initialize D0-D31 (64 words for 32 double regs) */ + *(--stk) = 0; /* FPSCR: Floating-Point Status and Control Register */ + *(--stk) = 0x40000000; /* FPEXC: Enable FPU (bit 30 = EN) */ #endif /* return task's current stack address */ |